However, the standard model for air-conditioned seats, developed by scientists at the Department of Energy's National Renewable Energy Laboratory (NREL), works like this: The fabric of the car seat is a porous mesh, so air can flow through it.
As chewing continues, the food is made softer and warmer, and the enzymes in saliva begin to break down carbohydrates in the food. After chewing, the food (now called a bolus) is swallowed. It enters the esophagus and via peristalsis continues on to the stomach, where the next step of digestion occurs.
Dysphagia is the medical term for difficulty swallowing. When dysphagia is mild, it may cause an individual only to stop eating for a minute or less, but when it is severe, it can prevent an individual from taking in enough calories for adequate nutrition.